Quick question ...I have been quoted £550 for a full turbo back system (Decat) for my S1, this is through a powerflow dealer in Newcastle. Anyone been to or knows anyone that has had an exhaust system created by them? Parts will be Tig welded and some MIG welded just wondering how loud it will be? don't want it to be deafening aha! also he said he recommends not putting the valves back into the exhaust because they can seize up? instead removing them ...whats everyones thoughts on this?